<?php
// +----------------------------------------------------------------------
// | CoreThink [ Simple Efficient Excellent ]
// +----------------------------------------------------------------------
// | Copyright (c) 2014 http://www.corethink.cn All rights reserved.
// +----------------------------------------------------------------------
// | Author: jry <59821125@qq.com> <http://www.corethink.cn>
// +----------------------------------------------------------------------
namespace Common\Model;
/**
 * 生成多层树状模型
 */
class TreeModel{
    //用于树型数组完成递归格式的全局变量
    private $formatTree;

    /**
    * 将格式数组转换为树
    *
    * @param array $list
    * @param integer $level 进行递归时传递用的参数
    */
    private function _toFormatTree($list, $level = 0, $title = 'title') {
        foreach($list as $key=>$val){
            $title_prefix = str_repeat("&nbsp;", $level*4);
            $title_prefix .= "└";
            $val['level'] = $level;
            $val['title_prefix'] = $title_prefix;
            $val['title_show'] = $level == 0 ? $val[$title] : $title_prefix.$val[$title];
            if(!array_key_exists('_child',$val)){
                array_push($this->formatTree,$val);
            }else{
                $title_prefix = $val['_child'];
                unset($val['_child']);
                array_push($this->formatTree,$val);
                   $this->_toFormatTree($title_prefix, $level+1, $title); //进行下一层递归
            }
        }
        return;
    }

    /**
    * 将格式数组转换为树
    *
    * @param array $list
    * @param integer $level 进行递归时传递用的参数
    */
    public function toFormatTree($list, $title = 'title', $pk='id', $pid = 'pid', $root = 0){
        $list = $this->list_to_tree($list, $pk, $pid, '_child', $root);
        $this->formatTree = array();
        $this->_toFormatTree($list, 0, $title);
        return $this->formatTree;
    }

    /**
     * 把返回的数据集转换成Tree
     * @param array $list 要转换的数据集
     * @param string $pid parent标记字段
     * @param string $level level标记字段
     * @return array
     */
    function list_to_tree($list, $pk='id', $pid = 'pid', $child = '_child', $root = 0) {
        // 创建Tree
        $tree = array();
        if(is_array($list)) {
            // 创建基于主键的数组引用
            $refer = array();
            foreach ($list as $key => $data) {
                $refer[$data[$pk]] =& $list[$key];
            }
            foreach ($list as $key => $data) {
                // 判断是否存在parent
                $parentId = $data[$pid];
                if ($root == $parentId) {
                    $tree[] =& $list[$key];
                }else{
                    if (isset($refer[$parentId])) {
                        $parent =& $refer[$parentId];
                        $parent[$child][] =& $list[$key];
                    }
                }
            }
        }
        return $tree;
    }

    /**
     * 将list_to_tree的树还原成列表
     * @param  array $tree  原来的树
     * @param  string $child 孩子节点的键
     * @param  string $order 排序显示的键，一般是主键 升序排列
     * @param  array  $list  过渡用的中间数组，
     * @return array        返回排过序的列表数组
     */
    function tree_to_list($tree, $child = '_child', $order='id', &$list = array()){
        if(is_array($tree)) {
            foreach ($tree as $key => $value) {
                $reffer = $value;
                if(isset($reffer[$child])){
                    unset($reffer[$child]);
                    tree_to_list($value[$child], $child, $order, $list);
                }
                $list[] = $reffer;
            }
            $list = list_sort_by($list, $order, $sortby='asc');
        }
        return $list;
    }
}
